Effects of a low-protein, high-fructose corn syrup diet on skeletal muscle and bone in young adult mice: a pilot study

[Purpose] This study aimed to examine the effects of chronic consumption of a low-protein diet combined with 10% high-fructose corn syrup (HFCS) on skeletal muscle and bone health in mice. [Methods] Seven-week-old male C57BL/6 mice were fed either a normal diet or a low-protein diet supplemented with 10% HFCS for 12 weeks. Gene expression in skeletal muscle was analyzed by real-time PCR, and bone microarchitecture was evaluated using micro-CT.[Results] Mice fed the low-protein diet supplemented with HFCS exhibited reduced body weight and lower gastrocnemius, heart, and femur weights. In the gastrocnemius muscle, genes related to muscle growth, glucose transport, and mitochondrial regulation were significantly downregulated, whereas no significant changes were observed in the soleus muscle. Additionally, trabecular bone volume fraction and number were significantly reduced, whereas cortical bone thickness remained unchanged.[Conclusion] Chronic intake of a low-protein diet supplemented with HFCS was associated with altered skeletal muscle metabolic gene expression, with potential differences between muscle types and changes in trabecular bone microarchitecture, suggesting potential adverse effects of combined nutritional stress on musculoskeletal health.